A climate-resilient Venice: how to respond to the challenges
Increasing impacts from climate change are causing environmental, economic and social pressure on coastal systems. These climate-related threats can be exacerbated by land use transformations, urbanization, over-tourism, socio-political tensions and technological innovations, among others.
The metropolitan city of Venice and its lagoon, located in northeastern Italy along the Adriatic coast, is a coastal-urban system that faces multiple challenges related to both changes in global phenomena and socio-economic dynamics.
With the aim of improving the overall resilience of the system to multiple climate-related disasters and a variety of other stressors, researchers from [email protected]’Foscari, the strategic partnership between the CMCC Foundation and the Ca’ Foscari University of Venice, conducted a study that identifies the best risk management initiatives for the region. Given the context of high uncertainty caused by climate change, the main objective was to identify strong initiatives in a range of possible future scenarios.
The study of prioritization of resilience initiatives for climate-related disasters in the metropolitan city of Venice was carried out within the framework of “BRIDGE”, a project of great importance for the cooperation between Italy and the United States. United, coordinated by Andrea Critto, professor at Ca’Foscari University of Venice and senior researcher at CMCC. He concludes that, given the situation of uncertainty, the best possible strategy is to use a portfolio of risk management initiatives – instead of a single initiative – to build resilience across the system. This set of measures should include physical initiatives – such as the adaptation of hydraulic defense structures to cope with large-scale and intense events – with cognitive and social initiatives – such as updating and implementing plans and regulations – which can be flexible enough to be effective against a range of hazards.
The study integrates qualitative information – derived from stakeholder participation in a workshop – and quantitative information derived from climate science (ie climate change projections).
At the start, different groups of local actors, including local authorities, civil protection agencies, research institutes, parks and NGOs identified critical system components (natural, cultural, social and economic) which should be protected in the region.
Second, stakeholders and experts identified a set of policy initiatives to support these essential functionsdivided into: Information initiatives (early warning systems and information generation and sharing); physical initiatives (networks of green and blue infrastructures, adaptation and optimization of the network and water supply, adaptation of hydraulic defense structures and emergency response systems); cognitive initiatives (updating and implementation of plans and regulations, planning of civil defense machinery; as well as plans and strategies for the restoration and recovery of historic areas); and social initiatives (environmental education and awareness and citizen science).
Finally, the above risk management initiatives have been rankedthrough scenario-based multi-criteria decision analysis (MCDA) through four scenarios describing the main climatic threats expected in the area: storm surges, storm floods, heat waves and drought.
The results show that different climate scenarios, when analyzed individually, lead to a specific prioritization of the set of risk management initiatives. Similarly, the priority of initiatives changes when considering the co-occurrence of several scenarios. However, given the great uncertainty surrounding the prediction of hazard scenarios that could occur in the future in this particular area, the best option is to strengthen the overall resilience of coastal systems to a series of adverse events.
Management alternatives acting on the physical domain, although prioritized by stakeholders, generally only build resilience in a few scenarios. These results can be explained by the fact that physical initiatives are generally designed and implemented targeting very specific typologies of extreme climate events. For example, the design of hydraulic defense structures and the implementation of emergency response devices, including fixed infrastructure projects like the MOSE – (MOdulo Sperimentale Elettromeccanico) or temporary solutions (for example, walkways, pumps and moveable partitions on private buildings and gates) are specifically designed for the protection of the Metropolitan City of Venice against storm surges and floods, while being unable to increase the resilience of the system against to other types of hazards, such as drought and heat waves.
On the contrary, cognitive, informational and social initiatives seem to be more stable under changing conditions, as they maintain their position when climate change scenarios are introduced.
The implementation of initiatives strongly oriented to deal with specific hazards could lead to an increase in risk towards other types of hazards (i.e. as a result, the study recommends adopting a portfolio of risk management initiatives to improve system resilience. These should include physical initiatives to deal with intense, large-scale events, as well as cognitive and social initiatives that can be flexible enough to be effective against a range of risks.
“Climate risks are interconnected and do not occur in isolation,” says Silvia Torresan, co-director of the Risk Assessment and Adaptation Strategies Division at the CMCC Foundation. “If we don’t employ a multi-hazard approach in risk assessment and management, we might adopt measures that address one problem but generate or amplify others.”
For more information:
Bonato M., Sambo B., Sperotto A., Lambert JH, Linkov I., Critto A., Torresan S., Marcomini A.
2021, Risk Analysis: An International Journal, Risk Analysis, Vol. 0, No. 0, 2021, DOI: https://doi.org/10.1111/risa.13823
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